Gyroscopes may be used in a wide range of applications, including guidance of aircraft, spacecraft, missiles, and the like. A gyroscope (or “gyro”) measures an angular rate, i.e., the rate at which the gyroscope is rotated, about one or more axes. The output of a gyroscope may be a digital data stream. The rate resolution of the gyro, i.e., the ability of the gyro to detect low angular rates or small changes in angular rate, may be limited in part by the resolution (i.e., the number of bits) and scale factor of an analog to digital converter (ADC) that may be part of a signal chain connecting a physical sensing element to a digital output of the gyro. The range of the gyro, i.e., the maximum angular rate that it is capable of measuring, may also be related to the resolution and the scale factor of the ADC. As such, a gyro designed to operate at high angular rates may have relatively poor resolution, and a high-resolution gyro may have relatively limited range. Some applications, however, may require a gyro having both high range, e.g., in aircraft or missiles designed to be highly maneuverable, and fine resolution, to provide accurate guidance.
MEMS gyroscopes can be vibrating structure gyroscopes, or “Coriolis vibratory gyroscopes”, which use a vibrating structure to determine their rate of rotation following the underlying physical principle that a vibrating object tends to continue vibrating in the same plane even if its support rotates. The Coriolis effect causes the vibrating object to for example exert a force on its support, and by measuring this force the rate of rotation can be determined. Vibrating structure gyroscopes are simpler and cheaper than conventional rotating gyroscopes of similar accuracy. Inexpensive vibrating structure gyroscopes manufactured with MEMS technology are widely used in smartphones, gaming devices, cameras and many other applications.
Known MEMS gyroscopes, such as disclosed in U.S. Pat. No. 7,168,318 (ISOLATED PLANAR MESOGYROSCOPE, to Challoner et al.) remain sensitive to their environment (temperature, vibration).
Environmentally-robust, high-performance inertial sensors with attractive CSWaP (Cost Size Weight and Power) are in strong demand in weapon, space and vehicle systems. There exists a need for a MEMS gyroscope that is less sensitive to its environment than known MEMS gyroscopes.